In the related art, in the process of manufacturing a superconducting accelerator tube, electron-beam welding is carried out to weld members. The electron-beam welding is accompanied with many additional tasks because vacuum drawing is essential, and positioning requires more time than welding in the air.
On the other hand, laser welding enables welding procedures in the air, and is applied to the process of manufacturing the superconducting accelerator tube, so that efficient manufacturing can be expected.
Patent Document 1 discloses a manufacturing method in which, on a butt weld zone of a straight pipe for a superconducting cavity, a groove has a stepped shape, and non-piercing welding is conducted from an inside and then non-piercing welding is conducted from an outside by a laser beam.